EP4140693A1 - Method for applying an adhesive film to a component and tool for same - Google Patents

Abstract

A method for applying an adhesive film to a component comprises the following steps: - providing a component (170), - providing an adhesive film (160) which comprises an adhesive layer, - applying the adhesive film (160) to a surface of the component (170) . To apply the adhesive film (160), this is positioned between the surface of the component (170) and an elastic membrane (120). The elastic membrane (120) is brought into a curved state with a convex and a concave side, at least in some areas, and is brought into contact with the surface of the component (170) with the convex side first, so that the adhesive layer of the adhesive film (160) is separated from the elastic membrane (120) is pressed onto the surface of the component (170) over its entire surface. The full-area pressing of the adhesive layer of the adhesive film (160) onto the surface of the component (170) is effected by the side of the elastic membrane (120) facing the adhesive film (160) being subjected to a negative pressure. To stabilize the component (170) against deformation caused by this negative pressure, the elastic membrane (120) together with the adhesive film (160) is pressed against the surface of the component (170) using a stamp (200). The invention also includes a corresponding tool.

Description

The invention described below relates to a method and a tool for applying an adhesive film to a component.

FIELD OF APPLICATION AND PRIOR ART

Adhesive films are used in many areas of application, for example for decorative purposes, such as transferring a color pattern to a surface, for functional reasons, such as protecting painted surfaces, or for applying lettering and the like. Above all, adhesive films are increasingly being used in the series production of motor vehicles, for example as stone chip protection, for applying model designations and, of course, for optical design purposes.

As a rule, the effort that arises when applying a color pattern using an adhesive film is significantly lower than when forming such a pattern in a multi-stage painting process. However, the application of adhesive foils in series production is anything but trivial. The larger the adhesive foil, the more difficult it is to position it correctly on the surface to be glued and to stick it without air pockets and wrinkling. Automation of these processes has not yet been successful. For example, the application of adhesive films in the series production of motor vehicles has been carried out manually to this day.

From the US6197397B1 adhesive films are known which comprise microstructured channels within the adhesive layer. These channels are intended to allow air to escape when the adhesive films are applied, in order to avoid air pockets and to make manual reworking to remove them superfluous. They are therefore more suitable for automated processing than classic adhesive films without the microstructured channels.

However, such adhesive films are very expensive. Furthermore, due to the microstructured adhesive layer, they are less suitable for the formation of high-quality surfaces. As a rule, adhesive films comprise a carrier film, one side of which is covered with an adhesive layer and the other side with an optionally multi-layer lacquer layer. When using very thin carrier foils, the microstructure leaves visible traces even after gluing. The use of particularly thick adhesive films is generally not desired. The problem can be solved with thick foils solve. However, these wear heavily on the substrate. Without overcoating with a clear coat, this does not lead to satisfactory results either.

From the applicant's as yet unpublished PCT application with reference number PCT/EP2019/086500 a method and a tool for applying an adhesive film to the surface of a workpiece are known, which address the problems mentioned. For this purpose, an adhesive film with an adhesive layer is positioned between the surface to be bonded and an elastic membrane with the help of an automated system. As a result of a negative pressure that is applied between the membrane and the surface, the membrane bulges towards the surface, forming a convex and a concave side, until it contacts the surface with the convex side first, so that the adhesive layer of the adhesive film of of the membrane is pressed onto the surface over its entire surface. The degree of curvature of the membrane is controlled by adjusting the pressure conditions on both sides of the membrane. It is thus possible, for example, to support the curvature of the membrane produced by applying the negative pressure by means of a corresponding excess pressure on the back of the membrane.

This procedure leads to excellent results with solid, structurally reinforced workpieces. However, problems arise when, for example, a very thin, flexible metal sheet is to be coated. In such cases, by applying the negative pressure mentioned, not only the membrane but also the metal sheet can be deformed, the latter possibly permanently. In addition, deformation of the surface to be bonded makes process control more difficult, since the distance between the surface and the membrane can change suddenly and in an uncontrolled manner.

A related method, but very different in details, is from DE 19812402 A1 known. This document deals with the application of foils to workpieces such as body panels. For this purpose, the film to be applied is converted into a convex shape and pressed against the surface to be coated. This is done with the help of a frame in which a membrane is clamped to which the foil is fixed. The foil is pressed on by means of negative pressure. In contrast to the one in the PCT/EP2019/086500 However, the method described does not describe a matching of the pressure conditions on both sides of the membrane. Instead, the rear space behind the membrane is filled with an elastic foam.

TASK AND SOLUTION

The invention described below was based on the object that from PCT/EP2019/086500 to improve known methods and the tool described. In particular, an automatable method and a tool for applying adhesive films should be developed, which can be integrated into series production, for example into a production line intended for the production of motor vehicles.

To solve this problem, the invention proposes the method with the features mentioned in claim 1 and the tool with the features mentioned in claim 10 . Developments of the invention are the subject of dependent claims.

1. a. Bereitstellen eines Bauteils,
2. b. Bereitstellen einer Klebefolie, die eine Klebeschicht umfasst, und
3. c. Aufbringen der Klebefolie auf eine Oberfläche des Bauteils.

The method according to the invention for applying an adhesive film always includes the following steps:

1. a. providing a component,
2. b. providing an adhesive film comprising an adhesive layer, and
3. c. Applying the adhesive film to a surface of the component.

• d. Die Klebefolie wird zwischen der Oberfläche des Bauteils und einer elastischen Membran positioniert, und
• e. die die elastische Membran wird zumindest bereichsweise in einen gewölbten Zustand mit einer konvexen und einer konkaven Seite überführt und mit der konvexen Seite voran mit der Oberfläche des Bauteils kontaktiert, so dass die Klebeschicht der Klebefolie von der elastischen Membran vollflächig an die Oberfläche des Bauteils gepresst wird, und
• f. das vollflächige Pressen der Klebeschicht der Klebefolie an die Oberfläche des Bauteils wird bewirkt, indem die der Klebefolie zugewandte Seite der elastischen Membran mit einem Unterdruck beaufschlagt wird, und
• g. zur Stabilisierung des Bauteils gegen eine durch diesen Unterdruck bewirkte Verformung die elastische Membran mitsamt der Klebefolie mit Hilfe eines Stempelmittels gegen die Oberfläche des Bauteils gedrückt wird.

For the application of the adhesive film according to the aforementioned feature c. the following features are provided according to the invention:

• i.e. The adhesive film is positioned between the surface of the component and an elastic membrane, and
• e. The elastic membrane is at least partially converted into a curved state with a convex and a concave side and with the convex side coming into contact with the surface of the component, so that the adhesive layer of the adhesive film is pressed by the elastic membrane over the entire surface of the surface of the component , and
• f. the full-area pressing of the adhesive layer of the adhesive film onto the surface of the component is effected by the side of the elastic membrane facing the adhesive film being subjected to a vacuum, and
• G. in order to stabilize the component against deformation caused by this negative pressure, the elastic membrane together with the adhesive film is pressed against the surface of the component with the aid of a stamping means.

The use of the membrane is particularly important for the process. This is preferably made as a layer formed of an elastic material and comprises two opposite flat sides. In order to press the elastic membrane against the surface of the component, the stamping means is preferably positioned in such a way that it can exert pressure on the side of the membrane facing away from the adhesive film.

To stabilize the component against the deformation caused by the vacuum, the elastic membrane is particularly preferably pressed together with the adhesive film against the surface of the component with the aid of the stamping means, so that the adhesive layer of the adhesive film is pressed against the surface in a point-like contact area. This results from the curvature of the membrane, which already results from pressing the stamping means against the side of the membrane facing away from the adhesive film. Furthermore, it also results from the application of the negative pressure. The negative pressure and the stamping means can bring about the curvature independently of one another and together.

In any case, the highest point of the curvature initially presses the adhesive film onto the surface in the punctiform contact area. If the negative pressure increases, other areas of the membrane are also pulled against the surface. The contact area then spreads out radially until the adhesive layer contacts the surface over its entire surface.

In particular, the stamping means is positioned relative to the membrane in such a way that the membrane bulges in the direction of the component as a result of the pressure of the stamping means and contact of the surface with the membrane or with the adhesive film positioned between the membrane and the surface occurs where the Membrane or the adhesive film would first come into contact with the surface without the stamping means, ie only pulled by the negative pressure.

In the method, the membrane and the adhesive film are preferably positioned over the surface to be bonded in such a way that the initial contact area is formed in a central area of the adhesive film and the surface to be bonded, so that the contact area extends from there in the direction of the edges of the adhesive film spreads. This minimizes the risk of air pockets.

Such a procedure is hardly possible with a conventional manual application of an adhesive film. For correct positioning of the adhesive film on the surface in manual application To ensure this, one edge of an adhesive film must always be manually aligned and pressed on first.

To set the negative pressure, a pressure difference is set between the two flat sides of the membrane, preferably by applying a lower pressure to the side of the elastic membrane facing the adhesive film than to the side facing away from the adhesive film. As a result, the elastic membrane is pulled or pressed in the direction of the component, depending on the perspective, so that the adhesive film can be pressed against the surface of the component.

As mentioned at the outset, the application of the vacuum to pressure-sensitive components, for example thin sheet metal, can cause an undesired deformation of the components. This problem is solved in the method according to the invention by using the stamping means, which presses against the surface of the component during this process and thus protects the component against deformation in the direction of the membrane and the adhesive film, in particular a bulge directed against the adhesive film. On the one hand, such a bulge would make it more difficult to evenly apply the adhesive film to the component, particularly if this bulge occurs suddenly. On the other hand, such a bulge could result in a permanent deformation of the component, which of course is also undesirable. These problems cannot occur when the stamping means is used to stabilize the component, so that the method described is particularly advantageous for applying adhesive films to structurally weak and/or very flexible components.

The pressure difference can be formed in different ways. For example, atmospheric pressure (1 bar) can be set in the area between the elastic membrane and the surface of the component and a pressure higher than atmospheric pressure can be set on the other side of the elastic membrane.

1. a. Der Unterdruck, mit dem der Klebefolie zugewandte Seite der elastischen Membran beaufschlagt wird, besteht relativ zu einem Druck, mit dem die der Klebefolie abgewandte Seite der elastischen Membran beaufschlagt wird und/oder einem Druck, mit dem eine Rückseite des Bauteils beaufschlagt wird.
2. b. Der Unterdruck ist ein Druck < 1 bar.
3. c. Zur Einstellung des Unterdrucks werden eine Unterdruckkammer, die von der der Klebefolie zugewandten Seite der Membran begrenzt wird, und eine Druckausgleichskammer, die von der der Klebefolie abgewandten Seite der Membran begrenzt wird, evakuiert, worauf die Druckausgleichskammer belüftet wird.

In a particularly preferred embodiment of the method according to the invention, at least one of the immediately following additional features a. to c. intended:

1. a. The negative pressure applied to the side of the elastic membrane facing the adhesive film is relative to a pressure applied to the side of the elastic membrane facing away from the adhesive film and/or a pressure applied to a rear side of the component.
2. b. The negative pressure is a pressure < 1 bar.
3. c. To adjust the negative pressure, a negative pressure chamber, which is delimited by the side of the membrane facing the adhesive film, and a pressure compensation chamber, which is delimited by the side of the membrane facing away from the adhesive film, are evacuated, whereupon the pressure compensation chamber is vented.

Preferably, the immediately above features a. and b. and c. implemented in combination.

In these preferred and advantageous embodiments of the method, a pressure <atmospheric pressure is set as the negative pressure, with a higher pressure relative to this, for example atmospheric pressure, prevailing on the other side of the membrane. The negative pressure is preferably in a range between 0.01 mbar and 1 bar, particularly preferably between 0.01 mbar and 750 mbar.

Depending on the size of the component and the area to be bonded, one or more stamping means can be provided. If a single stamping means is provided, this stamping means is preferably arranged in such a way that it presses the membrane together with the adhesive film against a central area of the surface to be bonded. If there are several stamping means, several pressure points are distributed over the surface to be glued.

The stamping means preferably comprises at least one extendable piston which is equipped with a stamping head, for example with a rounded stamping head. A rounded punch head is particularly advantageous because it does not leave any impressions or the like on the surface of the component. The piston can be extended in particular with an actuatable cylinder. In some embodiments, the stamp head itself is designed to be elastic or is covered with an elastic material.

1. a. Ein Vorschub des Stempelkopfes erfolgt in Koordination mit der Einstellung des Unterdrucks.

With regard to the extension of the at least one stamping means, ie with regard to the feed of the stamping means, the method according to the invention is characterized in a particularly preferred manner by the immediately following feature a. marked:

1. a. A feed of the punch head takes place in coordination with the setting of the negative pressure.

In other words, it is preferable to adjust the pressure difference, which leads to a Deflection of the elastic membrane leads, and the feed of the stamp means, coordinated.

1. a. Die Koordination des Vorschubs des Stempelkopfes mit der Einstellung des Unterdrucks erfolgt durch zeitliche Abstimmung.
2. b. Die Koordination des Vorschubs des Stempelkopfes mit der Einstellung des Unterdrucks erfolgt in Abhängigkeit von dem sich tatsächlich einstellenden Unterdruck.

In connection with the coordination of the setting of the pressure difference and the extension of the stamping means or means, at least one of the immediately following features a. and b. intended:

1. a. The coordination of the feed of the punch head with the setting of the vacuum is done by timing.
2. b. The coordination of the feed of the punch head with the setting of the negative pressure takes place as a function of the negative pressure that is actually set up.

In a particularly preferred manner, the stamping means is pressed on in a controlled or regulated manner. The actuation of the stamping means is in particular designed in such a way that the force acting on the component as a result of the pressure difference during the process of applying the film is compensated for and a force equalization thus occurs.

It is particularly preferred that the advancement of the stamping means and the setting of the pressure difference, in particular the setting of a negative pressure, take place at the same time. It is expediently taken into account here that in the case of pressure-sensitive components, deformation can begin right at the start of the evacuation, so that the stamping means is advantageously extended right up to contact with the component right at the start of the evacuation.

Provision can be made for the stamping means to be extended as a function of time. For example, after a few seconds or a predetermined time interval, z. B. 2 s or 3 s or 4 s or 5 s after the start of an evacuation, the stamp means are extended.

In other configurations, the plunger means can be extended as a function of an actually measured pressure acting on the membrane, ie in particular when the pressure falls below a predefinable threshold when the negative pressure is set. One or more pressure sensors can advantageously be used in this embodiment. For example, when a pressure of 100 mbar or another pressure threshold is reached, the plunger means can be extended. Such a regulation can in particular also be matched to the component to be bonded, in particular it can be varied depending on the pressure sensitivity of the respective component.

1. a. Die elastische Membran wird in einem ersten Schritt von dem automatisierten System an die Oberfläche des Bauteils herangeführt, und
2. b. im Bereich zwischen der zu beklebenden Oberfläche des Bauteils und der elastischen Membran wird in einem zweiten Schritt der Unterdruck angelegt, und
3. c. in einem dritten Schritt wird die elastische Membran mitsamt der Klebefolie mit Hilfe des Stempelmittels gegen die Oberfläche des Bauteils gedrückt, und
4. d. der Unterdrucks wird verstärkt, bis die Klebeschicht der Klebefolie von der Membran vollflächig an die Oberfläche gepresst wird.

A particularly preferred embodiment of the method according to the invention is characterized by the immediately following additional steps a. until d. out of:

1. a. In a first step, the automated system moves the elastic membrane to the surface of the component, and
2. b. in a second step, the vacuum is applied in the area between the surface of the component to be bonded and the elastic membrane, and
3. c. in a third step, the elastic membrane together with the adhesive film is pressed against the surface of the component with the aid of the stamping means, and
4. i.e. the negative pressure is increased until the adhesive layer of the adhesive film is pressed by the membrane across the entire surface.

Basically, in this embodiment, a temporal overlapping of step a. not possible with the remaining steps. The steps b. and c. and d. can generally overlap. In some preferred embodiments, however, step c. before step b. and step d. completed.

The terms "preparing" and "preparing" in the context of step a. immediately above. are to be interpreted very broadly according to the invention. In order to bring the membrane to the surface, the membrane can of course be moved towards the surface in the simplest case, but conversely the surface itself can also be moved towards the membrane. Only the distance between the surface and the membrane to one another is of interest when approaching it. Whether the membrane or the surface or both are moved to decrease the distance is not critical.

1. a. Der Unterdruck wird in Abhängigkeit des Drucks, den die Membran über die Klebefolie auf die zu beklebende Oberfläche ausübt, variiert.

As already indicated above, a negative pressure applied between the surface to be bonded and the elastic membrane can be varied in preferred embodiments to compensate for a contact pressure. Accordingly, in preferred embodiments, the claimed method is characterized by the immediately following feature a. out of:

1. a. The negative pressure is varied depending on the pressure that the membrane exerts on the surface to be bonded via the adhesive film.

For this purpose, an automated control or regulation mechanism can be provided, which automatically adjusts the negative pressure as a function of the desired contact pressure. In preferred embodiments, the actual pressures can be detected by sensors.

1. a. die Membran wird durch einen Überdruck oder mit Hilfe eines Überdrucks in den gewölbten Zustand überführt,
2. b. die Membran wird vor dem Anpressen der Klebefolie erwärmt oder gekühlt.

In a further preferred development of the invention, the claimed method is characterized by at least one of the immediately following steps a. and b. out of:

1. a. the membrane is brought into the curved state by overpressure or with the help of overpressure,
2. b. the membrane is heated or cooled before the adhesive film is pressed on.

The positive pressure can be used as an alternative to the negative pressure described above. It is essential to the method that the above-mentioned curvature occurs, and it is of secondary importance whether the formation of the curvature is supported or brought about by negative pressure or positive pressure.

The membrane can be heated completely independently of the use of negative and positive pressure. Shrinkage or stretching effects, for example, can be counteracted by heating or cooling the membrane.

1. a. Die elastische Membran besteht aus einem elastischen Polymermaterial, insbesondere aus Naturkautschuk oder Silikon.
2. b. Die elastische Membran weist eine gleichmäßige Dicke auf.
3. c. Die elastische Membran weist Schwächungs- und oder Verstärkungsbereiche zur gezielten Beeinflussung der Geometrie des gewölbten Zustands auf.

In a further preferred development of the invention, the elastic membrane used in the method is distinguished by at least one of the immediately following features a. to c. out of:

1. a. The elastic membrane consists of an elastic polymer material, in particular natural rubber or silicone.
2. b. The elastic membrane has a uniform thickness.
3. c. The elastic membrane has weakened and/or reinforced areas for specifically influencing the geometry of the curved state.

Particularly preferred are either the immediately above features a. and c. or b. and c. implemented in combination.

Influencing the geometry of the bulged state of the membrane can form the above mentioned punctiform contact area can be helpful. If there is an indentation in the surface to be bonded, the punctiform contact area should ideally be at the deepest point of the indentation. It may be preferable to avoid the formation of a circular contact area, since otherwise air pockets may occur.

For example, if the elastic membrane is thinner in one area than in another area, it will bulge more easily and further in this area when pressure or negative pressure is applied than in the other areas. The reverse applies in the case of reinforcement of the elastic membrane.

The introduction of areas of weakening and/or reinforcement into the elastic membrane can also be useful in order to influence the expansion of the contact area. This can be advantageous in particular when sticking the adhesive film onto curved surfaces, in particular onto surfaces with indentations.

1. a. Das Positionieren der Klebefolie zwischen der Oberfläche und der elastischen Membran erfolgt mit Hilfe einer Montagefolie, an der die Klebefolie mit ihrer der Klebeschicht abgewandten Seite haftet.
2. b. Zum Positionieren der Klebefolie wird die Montagefolie an oder in einem Rahmen fixiert.
3. c. Nach dem Anpressen der Klebefolie an die Oberfläche wird die Montagefolie von der Klebefolie abgezogen.

In a particularly preferred development of the invention, the claimed method is characterized by at least one of the immediately following steps a. to c. out of:

1. a. The adhesive film is positioned between the surface and the elastic membrane with the aid of a mounting film to which the adhesive film adheres with its side facing away from the adhesive layer.
2. b. To position the adhesive film, the mounting film is fixed on or in a frame.
3. c. After pressing the adhesive film to the surface, the mounting film is removed from the adhesive film.

At least steps a immediately above are particularly preferred. and c. realized in combination with one another, particularly preferably all steps a. to c..

Since the adhesive film, including its edges, should generally be pressed onto the surface to be bonded, the mounting film makes it easier to position. After the adhesive film has been pressed on, the mounting film is preferably pulled off the adhesive film.

The mounting film is preferably designed to be fixed to the frame. For this purpose, it can have positioning and fixing means that facilitate fixing to the frame.

The adhesive film is, for example, a decoration, lettering or one or more individual letters or decorative elements that are to be applied to the surface to be bonded.

It is possible to simultaneously transfer a number of adhesive films adhering to the mounting film to the surface to be bonded, for example if lettering comprising a number of letters or words is to be transferred to the surface. In this case, it is preferable to position the membrane and the adhesive film over the surface to be bonded in such a way that the initial contact area is formed in a central area of the lettering formed from a number of adhesive films.

1. a. Beschichtung einer Kraftfahrzeugkarosserie oder von Teilen einer Kraftfahrzeugkarosserie mit mindestens einem Lack.
2. b. Trocknen und/oder Aushärten des mindestens einen Lacks.
3. c. Gegebenenfalls Montage von Anbauteilen an tragende Komponenten der mit dem getrockneten und/oder ausgehärteten mindestens einen Lack beschichteten Kraftfahrzeugkarosserie.
4. d. Aufbringen der Klebefolie, die eine Klebeschicht umfasst, auf eine Oberfläche der mit dem getrockneten und/oder ausgehärteten mindestens einen Lack beschichteten Kraftfahrzeugkarosserie oder Teilen der Kraftfahrzeugkarosserie oder eines der daran montierten Anbauteile.

A particular advantage of the method according to the invention is that the method can be automated. In a particularly preferred manner, the method is therefore carried out using an automated system. In this embodiment in particular, it can be used with particular advantage, for example, in motor vehicle production. In this case, the component to be bonded is preferably a motor vehicle body or a part of a motor vehicle body or an add-on part of a motor vehicle. In this embodiment, the method preferably comprises two or more, in particular all of the immediately following steps a. to d.:

1. a. Coating of a motor vehicle body or parts of a motor vehicle body with at least one paint.
2. b. Drying and/or curing of the at least one lacquer.
3. c. Optional assembly of add-on parts on load-bearing components of the motor vehicle body coated with the dried and/or cured at least one paint.
4. i.e. Application of the adhesive film, which comprises an adhesive layer, to a surface of the motor vehicle body coated with the dried and/or cured at least one paint or parts of the motor vehicle body or one of the add-on parts mounted thereon.

The application of the adhesive film according to the aforementioned feature d. takes place in the manner described above, with at least one stamping means being used in order to stabilize the shape of the component during the application of the adhesive film and to avoid deformation.

The at least one paint is preferably a conventional multilayer automotive paint. Car bodies and body parts are usually primed, coated with a base coat and finally given a clear coat. The work and intermediate steps required for this are known. All that is important for the present invention is that the at least one lacquer on the substrate to be bonded has dried and cured, ie offers a pressure-resistant surface and no longer contains any solvent. As a rule, an application of clear lacquer is not necessary or not provided after the application of the adhesive film according to the invention.

The term "attachment" is to be interpreted broadly in the context of the invention. On the one hand, this includes unpainted parts such as panes or headlights, but on the other hand also painted parts such as a hood, a door, a fender and a roof element or colored plastic parts. If necessary, a paint was applied to these add-on parts separately from the motor vehicle body and dried and/or cured.

1. a. Die Klebefolie umfasst eine Trägerfolie, die auf einer Seite die Klebeschicht und auf einer anderen Seite eine Lackschicht aufweist.
2. b. Die Trägerfolie ist eine Kunststofffolie, eine Metallfolie oder eine Metall-Kunststoff-Kompositfolie.
3. c. Die Trägerfolie weist eine Dicke im Bereich von 10 µm bis 120 µm auf.
4. d. Die Klebeschicht weist eine Dicke im Bereich von 10 µm bis 80 µm, bevorzugt von 30 µm bis 60 µm, auf.
5. e. Die Klebeschicht weist eine gleichmäßige Dicke auf.
6. f. Die Klebeschicht besteht aus einer homogenen Klebemasse.
7. g. Die Klebeschicht weist eine Fläche im Bereich von 10 cm² bis 8 m² auf.
8. h. Die Lackschicht weist eine Dicke im Bereich von 20 µm bis 150 µm, bevorzugt von 30 µm bis 90 µm, besonders bevorzugt von 40 µm bis 60 µm, auf.

In a preferred development of the invention, the adhesive film that can be used in the method is characterized by at least one of the immediately following features a. until h. out of:

1. a. The adhesive film comprises a carrier film which has the adhesive layer on one side and a lacquer layer on the other side.
2. b. The carrier foil is a plastic foil, a metal foil or a metal-plastic composite foil.
3. c. The carrier film has a thickness in the range from 10 μm to 120 μm.
4. i.e. The adhesive layer has a thickness in the range from 10 μm to 80 μm, preferably from 30 μm to 60 μm.
5. e. The adhesive layer has a uniform thickness.
6. f. The adhesive layer consists of a homogeneous adhesive mass.
7. G. The adhesive layer has an area in the range from 10 cm ² to 8 m ² .
8. H. The lacquer layer has a thickness in the range from 20 μm to 150 μm, preferably from 30 μm to 90 μm, particularly preferably from 40 μm to 60 μm.

At least the immediately above features a are particularly preferred. and b. and G. implemented in combination. In a preferred development, the features a. until d. and G. and h., especially a. to e. and G. and h., in a particularly preferred embodiment, all features a. to h., realized in combination with each other.

The feature e. is particularly preferably implemented in combination with feature f. Uniform thickness means that the adhesive layer is not locally weakened by microstructure channels for evacuating air or other microstructures. It is preferably formed by applying a homogeneous adhesive mass using a squeegee and accordingly has a substantially flat and uniform surface. “Homogeneous” means that the adhesive mass contains no particles, in particular visible particles.

The use of microstructure-free adhesive layers makes it possible to use adhesive films with very thin backings in the method according to the invention while still being able to obtain a high-gloss "Class A surface". Carrier films with a thickness of 10 μm to 60 μm, preferably from 10 μm to 40 μm, are therefore more preferred within the above-mentioned range of 10 μm to 120 μm, especially if the adhesive layer is free of the microstructures mentioned.

1. a. Es umfasst eine elastische Membran, insbesondere in einer der oben beschriebenen Ausführungsformen, zum vollflächigen Anpressen der Klebefolie auf die Oberfläche des Bauteils, und
2. b. es umfasst mindestens ein Mittel zur Positionierung der Klebefolie zwischen der Oberfläche des Bauteils und der elastischen Membran, und
3. c. es umfasst ein Mittel zur Erzeugung eines Unterdrucks auf der der Klebefolie zugewandten Seite der elastischen Membran und/oder ein Mittel zur Erzeugung eines Unterdrucks auf der der Klebefolie abgewandten Seite der elastischen Membran, und
4. d. es umfasst mindestens ein Stempelmittel zum Drücken der elastischen Membran mitsamt der Klebefolie gegen die Oberfläche des Bauteils zur Stabilisierung des Bauteils während des Aufbringens der Klebefolie.

The invention also includes a tool for applying an adhesive film to a surface of a component. This tool is particularly suitable for carrying out the method described. The tool is always characterized by the following features:

1. a. It comprises an elastic membrane, in particular in one of the embodiments described above, for pressing the adhesive film onto the surface of the component over the entire surface, and
2. b. it comprises at least one means for positioning the adhesive film between the surface of the component and the elastic membrane, and
3. c. it comprises a means for generating a negative pressure on the side of the elastic membrane facing the adhesive film and/or a means for generating a negative pressure on the side of the elastic membrane facing away from the adhesive film, and
4. i.e. it comprises at least one stamping means for pressing the elastic membrane together with the adhesive film against the surface of the component to stabilize the component while the adhesive film is being applied.

The tool according to the invention can be used in particular for applying the adhesive film described above to the painted surface of a motor vehicle body, also described above, or an add-on part mounted thereon.

1. a. Es umfasst einen Rahmen, der dazu ausgebildet ist, gemeinsam mit derzu beklebenden Oberfläche und der elastischen Membran eine Unterdruckkammerzu bilden, in der die Klebefolie angeordnet ist und in welche die elastische Membran sich beim Beaufschlagen der Unterdruckkammer mit einem Unterdruck wölben kann.

In a particularly preferred embodiment, the tool according to the invention has the following additional feature:

1. a. It comprises a frame which is designed to form a vacuum chamber together with the surface to be bonded and the elastic membrane, in which the adhesive film is arranged and into which the elastic membrane can bulge when the vacuum chamber is subjected to a vacuum.

As already described, it is particularly advantageous to apply a vacuum when applying the adhesive film in the area between the surface to be bonded and the elastic membrane. The framework is provided for this.

The elastic membrane can be double-walled for temperature control purposes and have connections for a temperature control medium such as water.

In some particularly preferred embodiments, the membrane has the weakened and/or strengthened areas described above.

Since the adhesive film preferably adheres to the mounting film described above, the means for fixing the adhesive film is correspondingly preferably a means for fixing the mounting film.

The means for fixing the adhesive film or the mounting film can be, for example, pins or hooks that correspond to holes in the adhesive film or the mounting film.

1. a. Der Rahmen ist rechteckig ausgebildet.
2. b. Der Rahmen weist eine erste Öffnung auf, die von der Membran verschlossen ist.
3. c. Der Rahmen umfasst mindestens ein elastisches Dichtelement, das dichtend auf der Oberfläche aufliegen kann.
4. d. Der Rahmen umfasst eine zweite Öffnung, an deren Rändern das mindestens eine elastische Dichtelement fixiert ist.
5. e. Der Rahmen umfasst mindestens einen Anschluss für eine Unterdruckquelle, über den die Unterdruckkammer mit Unterdruck beaufschlagt werden kann.
6. f. Der Rahmen umfasst als Mittel zur Fixierung der Klebefolie mindestens eine Halterung.

In a preferred development of the invention, the tool is distinguished by at least one of the immediately following features a. to f. from:

1. a. The frame is rectangular.
2. b. The frame has a first opening which is closed by the membrane.
3. c. The frame includes at least one elastic sealing element that can rest sealingly on the surface.
4. i.e. The frame includes a second opening, at the edges of which the at least one elastic sealing element is fixed.
5. e. The frame includes at least one connection for a vacuum source, via which the vacuum chamber can be subjected to vacuum.
6. f. The frame comprises at least one holder as a means for fixing the adhesive film.

At least the immediately above features a are preferred. to e. realized in combination with each other, particularly preferably all features a. to f..

The at least one sealing element is used to seal off the vacuum chamber. They preferably consist of elastic polymer materials, for example the natural rubber already mentioned. The at least one connection for the vacuum source serves to generate the vacuum in the vacuum chamber.

1. a. Der Rahmen ist aus zwei oder mehr Teilrahmen zusammengesetzt.
2. b. Der Rahmen ist rechteckig ausgebildet und aus den zwei oder mehr rechteckigen Teilrahmen zusammengesetzt.
3. c. Der Rahmen umfasst einen ersten rechteckigen Teilrahmen, an dem das mindestens eine elastische Dichtelement fixiert ist und der den mindestens einen Anschluss für die Unterdruckquelle umfasst.
4. d. Der Rahmen umfasst einen zweiten rechteckigen Teilrahmen, der die mindestens eine Halterung für die Klebefolie umfasst.

In a further preferred development of the invention, the tool is distinguished by at least one of the immediately following features a. until d. out of:

1. a. The frame is composed of two or more sub-frames.
2. b. The frame is rectangular and composed of the two or more rectangular sub-frames.
3. c. The frame includes a first rectangular partial frame, to which the at least one elastic sealing element is fixed and which includes the at least one connection for the vacuum source.
4. i.e. The frame includes a second rectangular sub-frame, which includes the at least one holder for the adhesive film.

At least the immediately above features a are preferred. to c. realized in combination with each other, particularly preferably all features a. until th..

When using two or more sub-frames, it may be necessary to provide further sealing elements on connecting surfaces of the sub-frames in order to increase the tightness of the vacuum chamber guarantee.

For the purpose of controlling or regulating the vacuum as described above, the tool can have a suitable control or regulating device.

1. a. Es umfasst eine Druckausgleichskammer, die unter anderem von der Membran begrenzt wird.
2. b. Es umfasst mindestens einen Anschluss für eine Druck- oder eine Unterdruckquelle, der in die Druckausgleichskammer führt.
3. c. Es umfasst mindestens ein Ventil, über das die Druckausgleichskammer belüftet werden kann.

In a further preferred development of the invention, the tool is distinguished by at least one of the immediately following features a. to c., preferably by a combination of the immediately following features a. and b. or a. and c., from:

1. a. It includes a pressure compensation chamber, which is delimited by the membrane, among other things.
2. b. It includes at least one connection for a pressure or vacuum source that leads into the pressure equalization chamber.
3. c. It includes at least one valve via which the pressure compensation chamber can be vented.

This pressure equalization chamber may be required in order to produce or reinforce the curvature of the elastic membrane described. If a negative pressure is applied in the negative pressure chamber, it can be completely sufficient for this purpose to ventilate the pressure compensation chamber via the valve in order to bring about or increase the required curvature of the membrane.

The tool is particularly preferably fixed to an automated system, for example the arm of a robot. The tool, preferably including the automated system, is preferably arranged in an assembly line for the production of motor vehicles.

In principle, the method described and the tool described are of course not only suitable for use in the production of motor vehicles. For example, other series products can also be provided with adhesive films according to the invention, such as bicycles.

Further features and advantages of the invention described result from the drawings described below, in which preferred embodiments of the tool according to the invention are shown in different stages of the method according to the invention. The illustrated and described embodiments are only intended to illustrate and improve the understanding of the invention and are not to be taken as limiting in any way.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1

eine Schnittdarstellung durch ein erfindungsgemäßes Werkzeug vor oder zu Beginn der Durchführung des erfindungsmäßen Verfahrens; und

Fig. 2

eine Schnittdarstellung durch ein erfindungsgemäßes Werkzeug während der Durchführung des erfindungsmäßen Verfahrens.

In the figures, to illustrate the method according to the invention and the tool according to the invention, each show schematically

1

a sectional view through a tool according to the invention before or at the beginning of the implementation of the inventive method; and

2

a sectional view through a tool according to the invention during the implementation of the inventive method.

The Figures 1 and 2 show in cross section a tool 100 according to the invention, which is provided for applying an adhesive film 160 to the surface of a component 170, for example to a painted surface of a motor vehicle.

The tool 100 includes a rectangular frame composed of a rectangular sub-frame 130 and a rectangular sub-frame 140 (vacuum frame). The partial frames 130 and 140 are connected airtight via a seal 142 . A mounting film 150 is fixed to the partial frame 130 by means of a plurality of pins or similar fixing means that are not visible here. For this purpose, the mounting film 150 can have a plurality of holes, via which it can be hung on the pins or generally on corresponding fixing means.

An elastic membrane 120 made of natural rubber, for example, is arranged parallel to the mounting film 150 . It is clamped airtight between a base plate 110 and the partial frame 130 . It closes the opening of the frame defined by the partial frame 130 . For example, several screws (not visible here) or other fixing means can be screwed through the partial frame 130 into the base plate 110 for clamping.

The base plate 110 encloses a pressure compensation chamber 112 with the membrane 120 . Air can be admitted into the pressure compensation chamber 112 via a valve 114 .

A substructure can be attached to the side of the base plate 110 facing away from the elastic membrane 120, via which the tool 100 can be connected to a lifting tool or a robot.

The adhesive film 160, which is to be transferred to the surface 170 of the component, adheres to the side of the mounting film 150 that faces the surface of the component 170. FIG. The adhesive film 160 has an adhesive layer on the side that faces the surface of the component 170 . In particular, the adhesive film can be formed from a carrier film and a single-layer or multi-layer lacquer layer applied thereto and the adhesive layer, which is arranged on the side facing away from the lacquer layer. The adhesive film 160 can be a film part or several film parts, for example individual letters or ornaments or the like, which are to be applied together to the surface of the component 170.

The frame consisting of the partial frames 130 and 140 is designed to form a vacuum chamber 141 together with the surface of the component 170 to be glued and the elastic membrane 120, in which the mounting film 150 including the adhesive film 160 is located and in which the elastic Membrane 120 can bulge when the negative pressure chamber 141 is subjected to a negative pressure or a vacuum. For this purpose, the vacuum frame 140 is adapted to the geometry of the surface of the component 170, so that a form-fitting contact between the component 170 and the vacuum frame 140 is ensured.

An elastic sealing element 144 is fixed to the edges of the opening of the frame defined by the sub-frame 140, via which the frame is connected to the component 170 in a sealing manner. The vacuum chamber 141 can be evacuated via a connection 148 coupled to a vacuum source and the channel 146 guided through the partial frame 140 .

According to the invention, the tool 100 further comprises a stamping means 200 which is formed by a cylinder 201 , an extendable piston 202 and a stamping head 203 .

1 represents the state of the tool 100 with the adhesive film 160 contained therein in the initial state at the beginning of the implementation of the method. In this state, the pressure between the negative pressure chamber 141 and the pressure equalizing chamber 112 is balanced. The same pressure prevails in both chambers 141 and 112, for example atmospheric pressure (ambient pressure) or a negative pressure of 100 mbar. The elastic membrane 120 is not deflected, ie not arched.

2 represents the state during the further execution of the method in which the elastic membrane 120 is deflected in the direction of component 170. In this state, the elastic membrane 120 is curved. Its convex side presses the assembly film 150 and in particular the adhesive film 160 adhering to it against the surface of the component 170. The deflection of the elastic membrane 120 is caused by the extended plunger and a pressure difference between the vacuum chamber 141 and the pressure equalization chamber 112, with the vacuum chamber 141 a lower pressure than in the pressure compensation chamber 112 prevails.

This state of pressure difference can be achieved by reducing the pressure in the vacuum chamber 141 . This can be done by evacuating the vacuum chamber 141 via the port 148 . If at the same time the valve 114, which is provided for venting the pressure equalization chamber 112, is opened, the negative pressure in the negative pressure chamber 141 and the atmospheric pressure prevailing in the pressure equalization chamber 112 deflect the elastic membrane 120 in the direction of the surface of the component 170 in a curved shape . In other embodiments, it can also be provided that the areas on both sides of the elastic membrane 120, ie both the vacuum chamber 141 and the pressure equalization chamber 121, are first evacuated. In this phase, the elastic membrane 120 does not move, at least as long as the same pressure prevails on both sides. Only then is pressure equalization chamber 112 vented, so that the elastic membrane 120 is then deflected in the direction of component 170 as a result of the increase in pressure in pressure equalization chamber 112, at least if the membrane is not already in a curved state as a result of a corresponding pressure from the stamping means located.

The mounting film 150 with the adhesive film 160 is pressed against the surface of the component 170 by the curvature of the membrane 120 . As a rule, a first contact area 162 forms between the adhesive film 160 and the surface of the component 170, which spreads out radially as a result of an increasing negative pressure. Residual air, which may still be between the adhesive film 160 and the surface of the component 170, can thus always escape to the outside via the shortest possible route. If the contact area spreads further in the further course of the process, the entire surface of the adhesive film 160 comes into contact with the surface of the component 170 due to the full-surface pressing by the elastic membrane 120 and, as a result of the adhesive layer, reliably adheres to the surface of the component 170 .

The essence of the invention is that before or parallel to the formation of a pressure difference between the vacuum chamber 141 and the pressure compensation chamber 112, the piston 202 of the stamping means 200 extends with the punch head 203 located thereon and the elastic membrane 120 presses against the surface of the component 170 at certain points, with the adhesive film 160 lying between the membrane 120 and the component 170 . This measure stabilizes the shape of the component 170 and prevents the component 170, which can be, for example, an easily deformable, thin sheet metal, from being deformed by the negative pressure prevailing in the vacuum chamber 141 and in the direction of the interior of the tool 100 bulges or bulges.

After the adhesive film 160 has been pressed against the surface 170, the vacuum chamber 141 and the pressure equalization chamber 112 can be vented. The membrane 120 can then return to its original state. This also requires the stamping means 200 to return to the initial state. As a rule, the mounting film 150 is then pulled off the adhesive film 160. The adhesive film 160 remains on the surface 170.

Claims (15)

Method for applying an adhesive film to a component, comprising the steps a. providing a component (170), b. providing an adhesive film (160) comprising an adhesive layer, c. Applying the adhesive film to a surface of the component (170), wherein the following measures are taken to apply the adhesive film (160): i.e. The adhesive film (160) is positioned between the surface of the component (170) and an elastic membrane (120), e. the elastic membrane (120) is at least partially converted into a curved state with a convex and a concave side and is contacted with the convex side first with the surface of the component (170), so that the adhesive layer of the adhesive film (160) is separated from the elastic membrane (120) is pressed onto the surface of the component (170) over its entire surface, f. the full-surface pressing of the adhesive layer of the adhesive film (160) onto the surface of the component (170) is effected by the side of the elastic membrane (120) facing the adhesive film (160) being subjected to a vacuum, and G. to stabilize the component (170) against deformation caused by this negative pressure, the elastic membrane (120) together with the adhesive film (160) is pressed against the surface of the component (170) using a stamping means (200). Method according to Claim 1, characterized by at least one of the following features: a. The negative pressure applied to the side of the elastic membrane (120) facing the adhesive film (160) is relative to a pressure applied to the side of the elastic membrane (120) facing away from the adhesive film (160) and/or to a pressure , with which a rear side of the component (170) is applied. b. The negative pressure is a pressure < 1 bar. c. To set the negative pressure, a negative pressure chamber, which is delimited by the side of the membrane (120) facing the adhesive film (160), and a pressure equalization chamber (112), which is delimited by the side of the membrane (120) facing away from the adhesive film (160). , Evacuated, whereupon the pressure compensation chamber (112) is vented. Method according to Claim 1 or Claim 2, characterized by the following feature: a. The at least one stamping means (200) comprises at least one extendable piston (202) and a stamping head (203). Method according to one of the preceding claims, characterized by the following feature: a. A feed of the punch head (203) is carried out in coordination with the adjustment of the negative pressure. Method according to Claim 4, characterized by at least one of the following features: a. The coordination of the feed of the punch head (203) with the setting of the vacuum takes place through timing. b. The coordination of the feed of the ram head (203) with the setting of the negative pressure takes place as a function of the negative pressure that is actually set up. Method according to one of the preceding claims, characterized by at least one of the following additional features: a. The elastic membrane (120) consists of an elastic polymer material. b. the elastic membrane (120) has a uniform thickness. c. the elastic membrane (120) has weakened and/or reinforced areas for specifically influencing the geometry of the curved state. Method according to one of the preceding claims, characterized by at least one of the following additional features: a. The adhesive film (160) is positioned between the surface of the component (170) and the elastic membrane (120) with the aid of a mounting film (150) to which the adhesive film (160) adheres with its side facing away from the adhesive layer. b. To position the adhesive film (160), the mounting film (150) is fixed on or in a frame (130). c. After the adhesive film (160) has been pressed onto the surface of the component (170), the assembly film (150) is pulled off the adhesive film (160). Method according to one of the preceding claims, wherein the method is used for the production of motor vehicles and the component (170) is a motor vehicle body or part of a motor vehicle body or an add-on part, comprising the steps: a. Coating of a motor vehicle body or parts of a motor vehicle body with at least one paint, b. drying and/or curing of the at least one lacquer, c. Assembly of add-on parts on load-bearing components of the motor vehicle body coated with the dried and/or cured at least one paint, and i.e. Application of the adhesive film (160) to a surface of the motor vehicle body coated with the dried and/or cured at least one paint, the parts of the motor vehicle body or one of the add-on parts mounted thereon, wherein the adhesive film (160) is applied according to one of the preceding claims. Method according to one of the preceding claims, characterized by at least one of the following additional features: a. The adhesive film (160) comprises a carrier film which has the adhesive layer on one side and a lacquer layer on the other side. b. The carrier foil is a plastic foil, a metal foil or a metal-plastic composite foil. c. The carrier film has a thickness in the range from 10 μm to 120 μm. i.e. The adhesive layer has a thickness in the range from 10 μm to 80 μm. e. The adhesive layer has a uniform thickness. f. The adhesive layer consists of a homogeneous adhesive mass. G. The adhesive layer has an area in the range from 10 cm ² to 8 m ² . H. The lacquer layer has a thickness in the range from 20 μm to 150 μm. Tool (100) for applying an adhesive film (160) to a surface of a component (170), in particular in a method according to one of the preceding claims, characterized by the following features: a. It comprises an elastic membrane (120) for pressing the adhesive film (160) over the entire surface onto the surface of the component. b. It comprises at least one means for positioning the adhesive film (160) between the surface of the component (170) and the elastic membrane (120). c. It comprises a means for generating a negative pressure on the side of the elastic membrane (120) facing the adhesive film (160) and/or a means for generating a negative pressure on the side of the elastic membrane (120) facing away from the adhesive film (160). i.e. It comprises at least one stamping means for pressing the elastic membrane (120) together with the adhesive film (160) against the surface of the component (170) to stabilize the component (170) while the adhesive film is being applied. Tool according to Claim 10, characterized by the following additional feature: a. It comprises a frame which is designed to form a vacuum chamber (141) together with the surface of the component (170) to be glued and the elastic membrane (120), in which the adhesive film (160) is arranged and in which the elastic Membrane (120) can bulge when the vacuum chamber (141) is subjected to a vacuum. Tool according to Claim 11, characterized by at least one of the following additional features: a. The frame is rectangular. b. The frame has a first opening which is closed by the membrane (120). c. The frame has at least one elastic sealing element (144) which can lie sealingly on the surface of the component (170). i.e. The frame includes a second opening, at the edges of which the at least one elastic sealing element (144) is fixed. e. The frame includes at least one connection (148) for a vacuum source, via which the vacuum chamber (141) can be subjected to vacuum. f. The frame comprises at least one holder as a means for fixing the adhesive film (160). Tool according to Claim 11 or Claim 12, characterized by at least one of the following additional features: a. The frame is composed of two or more partial frames (130, 140). b. The frame is rectangular and is composed of two or more rectangular partial frames (130, 140). c. The frame includes a first rectangular partial frame (140) to which at least one elastic sealing element (144) is fixed and which includes at least one connection (148) for a vacuum source. i.e. The frame comprises a second rectangular partial frame (130) which comprises at least one holder for the adhesive film (160). Tool according to one of Claims 10 to 13, characterized by at least one of the following additional features: a. It comprises a pressure compensation chamber (112) which is delimited by the elastic membrane (120), among other things. b. It includes at least one connection for a pressure or vacuum source, which leads into the pressure equalization chamber (112). c. It comprises at least one valve (114) via which the pressure compensation chamber (112) can be vented. Tool according to one of Claims 10 to 14, characterized in that it is arranged in a production line for the production of motor vehicles.

Images